Road and building construction and many other earthworks projects can require transferring relatively large amounts of soil from one location to another. In some instances, the topography of a worksite needs to be altered by leveling the native soil, removing it, depositing soil in certain areas, etc. The project may specify a particular site topography for engineering purposes, land architecture or even aesthetics. Similarly, factors such as the lift thickness of sequentially deposited layers of fill soil, soil composition and moisture content may need to be strictly controlled. Numerous different machines such as compactors, tractors, haul trucks, scrapers, excavators, soil remediation machines and many others may all be used in preparing site topography and working soil in a given project. A site manager is often tasked with orchestrating the operation of all of these machines, with a premium placed on meeting deadlines, minimizing downtime and maximizing efficiency and quality. It will thus be appreciated that the overall process of preparing a worksite can be quite complex and demanding work.
Engineers and other individuals involved in earthworks construction practices have long recognized that soil moisture content tends to relate to the suitability of soil to serve as a supporting substrate or otherwise remain stable over time. The relative ease of working soil in anticipation of its end use, such as by compacting, may also be affected by moisture content. Overly dry soil may undergo physical changes as time passes and moisture penetrates, compromising the soil's integrity as a supporting substrate. Wet soil can likewise shift or otherwise become unstable over time. It may also be difficult to achieve proper compaction of soils having improper moisture content, though the resulting problems may not become apparent until later. Achieving an optimum moisture content in fill soil is thus preferred, and often critical, to a project's long-term success.
As mentioned above, site preparation for many earthworks projects can require transferring relatively large volumes of soil from one location to another. It is common for site engineers to select a “cut area” for obtaining fill soil, and a “fill area” where transferred fill soil is to be deposited. Fill soil is typically transferred via haul trucks or scraper machines from a cut area to a fill area in stages, each time laying down a layer or “lift” of soil which is subsequently compacted with compactor machines to a presumably proper compaction state. If soil having an improper moisture content, e.g. too wet or too dry, is deposited in one or more of the lifts, however, labor intensive re-working of the soil is often required. Soil which is too dry may be moistened by spraying water on the soil with a water truck. Soil which is too wet is often disked to mix it and increase the available surface area for ambient drying. Discerning whether soil has the appropriate moisture content prior to its deposition, however, has heretofore been challenging or impossible in most instances.
Present practice is therefore to measure soil moisture at the end of a construction phase, for example with moisture/density meters. Such meters are used to determine whether the relative amount of water within a certain sample of soil is either too high or too low, and can determine the overall density of a sample. If the soil is not at a desired moisture content or not compacted sufficiently, the aforementioned reworking techniques are typically used, and the soil once again compacted. Rework of already laid soil to obtain an appropriate moisture content consumes a substantial proportion of manpower and resources in many earthworks projects. It also reduces the economic viability for contractors and takes time. It will thus be readily apparent that advances in soil moisture control and/or monitoring prior to depositing soil at a fill site would be welcomed in the construction industry.
The present disclosure is directed to one or more of the problems or shortcomings set forth above.